It is already known from DE 2,335,701 that an outer ring for a ball bearing can be pressed into a runner shell and that this can then be secured axially by wedging a ring over it.
The material of the runner shell which projects axially beyond the seating surface is thus axially deformed, i.e., flattened and bent over, and thus a certain amount of material is pushed against the outer ring in the radial and axial directions. As a result, a reliable, positive form-locking connection is achieved.
When runner shells are drawn (formed by pressing a die into a flat sheet of metal) the resulting edge material from which the bent over wedge is formed is not uniform in thickness, axial height, and radius of curvature. In prior art, the ring shaped die uniformly compresses the edge material around the outer ring of the bearing causing non-uniform stresses on the outer ring of the bearing leading to unallowable deformation of the outer ring pushing it out of its circular shape. This deformation leads to premature failure of the roller bearing. The way to prevent this unallowable deformation is to uniformly deform edge material such that the stresses and hence deformation is uniform around the outer ring.
This invention solves that problem by making the ring shaped forming or wedging surface or edge deforming die non-uniform in height so that during the edge forming process the same amount of material and thus equal stresses are formed around the circumference of the outer ring of the bearing